This request is for funds to purchase a FACSAria cell sorter. This instrument will be housed within the newly created Department of Immunology at the University of Pittsburgh. At present there is no cell sorter available for use by primary and many of the secondary faculty in the Department and thus this purchase will have an enormous impact on the Immunology community at the University of Pittsburgh. Existing cell sorters at the University of Pittsburgh are either not available to Department members or are located several miles away from the Department. The ability to perform high speed cell sorting is an essential feature of much immunology research. Thus the reasons for this application are to: 1) Provide a critically needed instrument; 2) provide an easy-to-use readily accessible cell sorter for primary and secondary Immunology faculty; and 3) form the basis of the newly created Immunology Flow Facility. In January 2002 a new Department of Immunology was created in recognition of the strength of the immunology research performed here at the University of Pittsburgh. At present there are 30 primary and secondary faculty in the Department of Immunology and most of them are NIH-funded. The acquisition of the requested cell sorter will allow individual users access to cell sorting, which is at present unavailable to many members of the Department. [unreadable] [unreadable]